Modern vehicles typically have a vehicle diagnostic system, including one or more separate computer control modules. Examples of such computer control modules (also known as just “modules”) are: a powertrain control module (PCM), an engine control module (ECM), a transmission control module (TCM), an ABS control module, and an air bag control module.
“Off-board devices,” such as scan tools and code readers are known in the art. Scan tool and code reader testing devices interface with vehicle diagnostic systems to, e.g., access, display, and/or print vehicle diagnostic information. OBD II (On-Board Diagnostics version II) Scan Tools are one commonly known type of scan tool and are governed by a number of standards, e.g., SAE J1978 Rev. 1998-02 and SAE J1979 Rev. 1997-09. Scan tools are relatively expensive diagnostic devices that have a relatively large number of features and are typically marketed to professional automobile mechanics and service stations. Scan tools are generally considered to be beyond the means of most automobile hobbyists and the ordinary individual interested in performing simple maintenance or service of a few vehicles, such as a family “fleet” of vehicles.
There are different types of scan tools. An “OBD II Scan Tool” complies with the above-identified specifications. By contrast, a “Manufacturer-Specific Scan Tool” is a scan tool that accesses and displays proprietary manufacturer-specific data (and possibly also additionally accesses and displays OBD II data). Examples include Device Controls on General Motors, On-Demand Tests in Ford, Actuator Tests, Sensor Tests, Interrogator, and Read Temporary Codes in Chrysler. In general, air bag data, ABS data, cruise control data, and climate control data are also considered to be proprietary manufacturer-specific data and are typically included only in Manufacturer-Specific Scan Tools.
An “off-board device” that is a low-cost alternative to the scan tool is a “code reader.” In 1998 Actron Manufacturing Corp., the assignee of the present invention, pioneered the first OBD II code reader. In contrast with a scan tool, a code reader is a relatively basic “off-board device” that links with one or more computer modules in a vehicle diagnostic system via a vehicle computer network, reads any diagnostic trouble codes (also referred to as just “diagnostic codes” herein) asserted by those vehicle diagnostic systems, and displays any diagnostic codes on a display. Typical code readers do not perform the following major functions that are performed by typical scan tools: “View Data,” also known as “Live Data,” “Data,” and “Data Test, DTC” (viewing and displaying in real-time live, changing data from a plurality of module sensors), display of textual diagnosis descriptions corresponding to the various diagnostic codes, recording and playback of data, device control (manually controlling modules for diagnostic purposes), and reading and displaying vehicle information from the vehicle's computer (e.g., VIN information, controller calibration identification number, etc.). Code readers are typically marketed to automobile hobbyists and non-professionals who are merely curious about what codes the various vehicle diagnostic systems have stored in their memories.
Off-board devices typically do not include test circuits. Rather off-board devices, such as scan tools and code readers, typically communicate with the vehicle diagnostic system, which does typically include one or more test circuits. Thus, typical off-board devices do not perform any tests themselves; with few exceptions (e.g., the NGS scan tool with its harness tester, “sensor simulation”), off-board devices merely report the results of tests performed by test circuitry external to the off-board device.
One expense involved in manufacturing scan tools is the costs of the parts, such as the processor, circuit boards, display, housing and input keys. Another expense associated with scan tools is the software that needs to be installed on the device. There are many different makes and models of automobiles, many of which have specialized codes and error messages. In addition, since vehicle manufacturers add new equipment, codes and faults, it is often necessary to update the software to include the new codes and faults every time a new model year is introduced. Further, most scan tools are equipped to handle the communications protocols and error/fault messages of most, if not all, of the vehicles on the market. This requires the scan tool to store a large number of error/fault codes and many different communications protocols. As a result, the cost of the scan tool is beyond the reach of the average back yard mechanic, who only has one or two automobiles.
Cellular phones are commonplace in today's society and have processors, circuit boards, displays, housings and input keys. Further, most cellular phone service providers offer free cellular phones to people who sign a contract to use the provider's service for a minimal period of time, generally two years. At the end of the two year contract, most people simply discard the old cellular phone and obtain a new cellular phone with a new contract. Further due to economies of scales, cellular phones have become inexpensive and common place.